1. Field of the Invention
The invention relates to a cartridge for ink-jet printer.
2. Description of the Related Art
The existing cartridge matching to ink-jet printer includes a cartridge body, a protective cover moving relatively to the cartridge body under pressure, a detection mechanism for cartridge and a detection mechanism for remaining ink volume, wherein the cartridge body includes an ink storage cavity, an ink outlet for providing ink to the printer head and an air inlet. The cartridge must include two detection mechanisms in order to ensure the normal operation of cartridge after installed in the printer. During the installation process of cartridge on the printer, one detection mechanism at first prevents the light from the emission unit of the second sensor from returning to the reception unit of the second sensor, and then allows such light to return to the reception unit of the second sensor. After that, the other detection mechanism prevents the light from the emission unit of the first sensor from returning to the reception unit of the first sensor, and finally, the light from the reception unit corresponding to the first and second sensors is prevented from returning to corresponding reception unit. Installation detection is completed after that. Then the printer gives a prompt that cartridge installation is completed to go to the next operation. The mechanism of the existing cartridge for detecting cartridge and ink volume is shown as FIG. 1, comprising the first detecting unit a, the second detecting unit b, the third detecting unit c, a light transmission unit d and a movable lever e. The detection mechanism of this plan is realized by sheltering the light from sensor, whereof the operating principle is as follows: when cartridge is installed in the printer, the light from the second sensor in the printer is sheltered by the second lightproof detecting unit b initially and then connected without the shelter of the second lightproof detecting unit b with the installation of cartridge. After that, the light from the first sensor is sheltered by the first detecting unit a, and finally the light from the second sensor is also sheltered by the third lightproof detecting unit c, whereafter the printer gives a prompt of the existence of cartridge for the next operation. The said third detecting unit c is comprised of a light transmission unit d and a lightproof movable lever e, the position of the latter may vary with the ink volume in the cartridge, and the light from the second sensor can detect the ink volume in the cartridge according to the fact whether the light is sheltered by the third detecting unit c. From the above, it is clear that the installation detection for cartridge must use the detection mechanism for remaining ink volume, the sheltering of the third detecting unit in another word, to realize that the installation detection for cartridge shall not be completed independently without the influence of remaining ink volume. For example, when the installation of cartridge without ink is completed, installation is completed in actual, but the printer may give a prompt that installation is not completed, resulting that the alarming of installation incompletion and of no ink can not be distinguished definitely.